Effect of Substitutional Oxygen on Properties of Ti3 C2 Tx MXene Produced Using Recycled TiO2 Source.

MXenes are an emerging class of 2D materials with unique properties including metallic conductivity, mechanical flexibility, and surface tunability, which ensure their utility for diverse applications. However, the synthesis of MXenes with high crystallinity and atomic stoichiometry in a low-cost process is still challenging because of the difficulty in controlling the oxygen substitute in the precursors and final products of MXenes, which limits their academic understanding and practical applications. Here, a novel cost-effective method is reported to synthesize a highly crystalline and stoichiometric Ti3 C2 Tx MXene with minimum substitutional oxygen impurities by controlling the amount of excess carbon and time of high-energy milling in carbothermal reduction of recycled TiO2 source. The highest used content (2 wt%) of excess-carbon yields TiC with the highest carbon content and minimal oxygen substitutes, which leads to the Ti3 AlC2 MAX phase with improved crystallinity and atomic stoichiometry, and finally Ti3 C2 Tx MXene with the highest electrical conductivity (11738 S cm-1 ) and superior electromagnetic shielding effectiveness. Additionally, the effects of carbon content and substitutional oxygen on the physical properties of TiC and Ti3 AlC2 are elucidated by density-functional-theory calculations. This inexpensive TiO2 -based method of synthesizing high-quality Ti3 C2 Tx MXene can facilitate large-scale production and thus accelerate global research on MXenes.

Corrosion Protection Oxide Scale Formed on Surface of Fe-Ni-M (M = Al, Cr, Cu) Inert Anode for Molten Salt Electrolysis.

An oxide scale formed on the surface of metal anodes is crucial for determining the overall quality of molten salt electrolysis (MSE), particularly for the durability of the anode materials. However, the material properties of oxide scales are yet to be revealed, particularly in ternary spinel oxide phases. Therefore, we investigate the mechanical and thermal properties of spinel oxides via first-principles calculations. The oxides are calculated using the models of normal (cubic) and inverse (orthorhombic) spinel compounds. The d-orbital exchange correlation potential of transition metal oxides is addressed using the generalized gradient approximation plus Hubbard U. The lattice constant, formation energy, cohesive energy, elastic modulus, Poisson's ratio, universal anisotropy index, hardness, minimal thermal conductivity, and thermal expansion coefficient are calculated. Based on the calculated mechanical and thermal properties of the spinel compound, the Fe-Ni-Al inert anode is expected to be the most suitable oxide scale for MSE applications among the materials investigated in our study.

Arteriovenous fistula patency associated with angiotensin-converting enzyme I/D polymorphism and ACE inhibition or AT1 receptor blockade.

BACKGROUND: Compromise of arteriovenous fistula (AVF) patency is caused by venous intimal hyperplasia. Many studies indicated that the renin-angiotensin-aldosterone system plays an important role in the development of intimal hyperplasia. Here we determined whether angiotensin-converting enzyme (ACE) I/D polymorphism is an independent prognostic factor for AVF patency in hemodialysis (HD) patients. METHODS: One hundred and fifty-five HD patients with native AVF were enrolled and genotyped, retrospectively. The primary end point was unassisted patency of the AVF, which was defined as the time from the first fistula surgery to the AVF failure. RESULTS: The unassisted AVF patency at 58 months was 47.0% in the DD genotype group and 71.8/82.9% in ID/II groups (p < 0.01). ACE inhibitors (ACEI) or angiotensin II receptor blockers (ARB) intake had significant impact on AVF patency in the ACE DD group (p = 0.03). Using a Cox-adjusted model, we observed a significant correlation between the increase in the incidence of AVF failure and diabetic nephropathy, higher mean serum phosphorus level, and the ACE DD genotype. CONCLUSION: The ACE I/D polymorphism was associated with the development of AVF failure, and a preventive role of ACEI or ARB intake on AVF patency in ACE DD patients was observed.

Bloodletting-induced cardiomyopathy: reversible cardiac hypertrophy in severe chronic anaemia from long-term bloodletting with cupping.

Cardiac hypertrophy in a patient with severe iron deficiency anaemia associated with long-term bloodletting using cupping, called 'puhang' in oriental medicine, is discussed using chest electrocardiographic and radiographic images. With iron supply, the patient showed remarkable improvement of cardiomegaly, which is a unique feature of chronic severe iron deficiency anaemia.

Fanconi's syndrome and subsequent progressive renal failure caused by a Chinese herb containing aristolochic acid.

Chinese herb nephropathy contains a variety of clinical features of progressive renal failure (indicated by studies conducted in Belgium) to the variant type of Fanconi's syndrome. Fanconi's syndrome has mostly been reported in Asian countries, and is characterized by proximal tubular dysfunction and slower progression to end-stage renal disease (ESRD); it also often revealed a reversible clinical course. We describe a 43-year-old woman who presented with polyuria and polydipsia caused by Fanconi's syndrome. The cause of Fanconi's syndrome was not identified because the patient denied the intake of the Chinese herbal mixture at first. Fanconi's syndrome seemed to be reversible in its early stage, but it rapidly progressed to renal failure after 3 months, despite the interruption of Chinese mixture use. A renal biopsy revealed typical findings of aristolochic acid-induced nephropathy. Aristolochic acids were also detected in the Chinese herbs that were consumed. This case highlights the variety of the clinical spectrum of aristolochic acid induced nephropathy (AAN). We emphasize that AAN should be suspected in all patients with Fanconi's syndrome, even if patients deny the intake of any Chinese herbal preparation.

Identification of novel mutations in Na-Cl cotransporter gene in a Korean patient with atypical Gitelman's syndrome.

The authors report the case of a 20-year-old man with unexplained hypokalemia and metabolic alkalosis suggesting hypokalemic tubulopathy. Interestingly, he showed a mixed phenotype of Gitelman's syndrome (GS) and Bartter's syndrome, which includes normomagnesemia, normal renal magnesium excretion, and hypocalciuria. Renal clearance study showed the presence of a critical defect in the distal nephron rather than loop of Henle. Further family study showed that his mother had a definitive phenotype of GS. By the molecular genetic analysis of these patients, 7 different mutations of the NCCT gene were identified consisting of 3 missense, 1 splice site, and 3 silent mutations. Four of these mutations were novel. The authors emphasize that the combination of a molecular genetic approach and renal clearance study could be of practical benefit in confusing clinical setting and support new diagnostic criteria in GS.